Mastitis is an inflammation of the mammary gland that is caused by bacteria which in most cases enter the gland via the teat orifice. Deposits of keratin in the teat orifice and the streak canal form a primary defence mechanism. Keratin contains high levels of naturally occurring anti-bacterial substances which inhibit the passage of bacteria from the teat orifice to the cistern (papillary sinus).
The defensive plug of keratin that accumulates in the streak canal is dislodged during milking. Furthermore, the keratin plug has increased mass in dry cows than lactating cows. Susceptibility to mastitis is exacerbated by regular milking, particularly by mechanical milking processes that result in damage to the tissues of the teat in the vicinity of the teat orifice. If the keratin plug does not reform properly after milking ceases at drying off, a cow is much more likely to develop mastitis during the non-lactation period and when milking recommences.
International application number PCT/NZ2004/000231 (Publication No. WO 2005/027775) describes a device to promote the deposition and retention of endogenous keratin within the teat canal. In addition, the device may be made of a preformed matrix such as silicone which is able to deliver treatment substances. The device is contrasted with low viscosity pastes and gels that are not able to provide precise positioning of substance for control over the volume of composition infused.
The device is retained in the teat orifice and is required to be removed prior to milking. This requirement introduces an additional step in the manually intensive procedure of milking cows.
International application number PCT/SE98/00776 (Publication No. WO 98/48627) describes a teat dipping solution for lactating cows. The teat dipping solution is used prophylactically or as a wound healing treatment against mastitis. The teat dipping solution comprises chitosan in combination with a polysaccharide selected from heparin, heparin sulphate, and dextran sulphate.
The composition described is an alternative to other veterinary compositions for reducing mastitis such as those described in U.S. Pat. No. 4,472,374. These latter compositions are introduced directly into the teat canal. During the introduction of these compositions into the teat canal endogenous keratin that may have been deposited is dislodged, thereby diminishing the natural defence to infection. Furthermore the use of these compositions may place restrictions on when the milk collected from treated cows, may enter the human food chain.
The trade name products TEATSEAL and ORBESEAL are anti-microbial compositions. These products comprise bismuth subnitrate in an oily base. The composition is supplied in an injector for infusing the composition into the teat to form a seal. Milk collected from animals within three days of this treatment and intended for human consumption must be discarded. Accordingly, there is a commercial disadvantage to farmers if milk or colostrum collected from treated cows cannot be sold.
An object of the present invention is to overcome one or more of the disadvantages of the prior art, or at least to provide the public with a useful choice.